Gasoline compositions containing diphosphonates



United States Patent 3,414,393 GASOLINE COMPOSITIONS CONTAINING DIPHOSPHONATES Steven J. Fitch, Creve Coeur, and Riyad R. Irani, Florissant, Mo., assignors to Monsanto Company, a corporation of Delaware No Drawing. Original application Feb. 9, 1963, Ser. No. 271,607, now Patent No. 3,299,123. Divided and this application Aug. 29, 1966, Ser. No. 590,449

2 Claims. ('CI. 44-76) ABSTRACT OF THE DISCLOSURE The present invention relates to and covers gasoline compositions which contain organo-methylene diphosphonic esters such as for example tetramethyl methylene diphosphonate.

PCP

group in their molecules.

A further object of this invention is to provide new and useful organic compounds of phosphorus containing a group in their molecules with the C35 group being a hydrophobic and/ or lipophilic group.

A further object of this invention is to provide new and useful organophosphonic acids, as 'well as their salts and esters.

A more specific object of this invention is to provide new and useful organo-methylene diphosphonic acids or the salts thereof which exhibit, among other things, combined surfactancy, sequestering and defiocculating properties.

A more specific object of this invention is to provide new and useful organo-methylene diphosphonate esters which exhibit, among other things, the unique ability of solubilizing water in water immiscible solvents.

Another object of this invention is to provide detergent compositions containing organo-methylene diphosphonic acids or the salts thereof.

Another object of this invention is to provide detergent compositions containing organo-methylene diphosphonic acids or the salts thereof which are suitable for use in aqueous systems.

Another object of this invention is to provide detergent compositions containing organo-methylene diphosphonate esters.

A still further object of this inveniton is to provide detergent compositions containing organo-methylene diphosphonate esters which are suitable for use as dry-cleaning detergents in organic solvents.

A still further object of this invention is to provide gasoline additive compositions containing organo-methylene diphosphonate esters.

3,414,393 Patented Dec. 3, 1968 XOOROOX wherein: R is selected from the class consisting of aliphatic hydrocarbyl, alicyclic, .aryl, alkaryl, aralkyl groups of from 5 to 30 carbon atoms and carbon containing heterocyclic groups and X is selected from the class consisting of cations selected from the group consisting of hydrogen ions, alkali metal cations, alkaline earth metal cations, aluminum cations, ammonium ions and amine ions, and aliphatic hydrocarbyl, aryl, .alkaryl and aralkyl groups of from 1 to 30 carbon atoms. When the symbols R and X represent groups containing carbon chains, such as aliphatic hydrocarbyl groups, or groups containing alkyl moieties, i.e., aralkyl groups, such carbon chains may be of a straight chain structure or branched chain structure. For the symbols R and X when they represent aliphatic hydrocarbyl groups, such groups may be saturated or unsaturated. The above mentioned groups which are represented by R can also contain substituents, such as, hydroxyl, halides, i.e., fluoride, chloride, bromide and iodide, alkoxy groups, ester groups, ether groups, nitro groups, sulfonyl groups, amide groups, amino groups, carboxyl groups, nitroso groups and the like as long as they do not materially interfere with the hydrophilic and/or lipophilic nature of groups. For most end use applications the compounds of the instant invention should preferably contain not more than 25 carbon atoms associated with R and X (when X represents ester groups), and there are few, if any, end uses, in which the foregoing groups contain more than a total of 50 carbon atoms.

These compounds can be characterized quite generally has having a P-CP linkage in their molecules and are generically described in this specification by the general terms organo-methylene diphosphonic acids, the salts of organo-methylene diphosphonic acids, and the esters of organo-methylene diphosphonic acids.

The compounds of the invention can be prepared by Various methods with the following methods presented as being representative of their preparation.

The ester of the organo-methylene diphosphonic acids can be prepared by first forming a metallo-derivative of a methylene diphosphonate ester and reacting this metalloester derivative with an organo-halide to produce the desired organo-methylene diphosphonate ester. The reaction of the metallo-ester derivative with the organo-halide is believed represented by the following equation:

wherein R represents the same groups as in the foregoing general Formula 1.

In general, metallo-derivatives of the tetra-ester methylene diphosphonate can be prepared in several ways. When preparing the Group IA (alkali metals) ester derivatives and particularly the sodioand potassio-ester derivatives it is usually only necessary to react the alkali metal directly with the ester. The reaction is often exothermic so that, in most cases, it may be necessary to bring the reactants together while cooling, to dilute the mixture with an inert solvent such as xylene, benzene, toluene, ether, dioxane, hexane and the like, or to add the sodium or potassium slowly to the esters in the inert solvent. In some cases'it may be necessary to employ all of the immediately -silver-ester derivative and cuprousester derivative; the

Group II-B metal derivatives, and in particular the zincester derivative; and Group IV-A metal derivatives, and in particular the leadand tin-ester derivatives by methods which are similar to the foregoing methods. Because of the relative inexpensiveness and the ready availability of sodium and potassium and because of their rather straight forward reaction with the ester it is generally advantageous to form the sodioand potassio-ester derivatives and, therefore, sodium and potassium are the preferred metals for use in forming these ester derivatives.

In general, the reaction of the metallo-ester derivatives with an organo halide, i.e., reaction (2), is relatively straight forward. Often times, however, it may be necessary to use temperatures above room temperature, i.e., about C., in order to facilitate the reaction with temperatures of between about 70 C. to about 180 C. usually being sufficient. In most cases, depending on the temperature used, a definite precipitate forms, i.e., metalhalide, after a period of time of between about 10 minutes and about 4 hours. The precipitate may be removed by several well known methods, such as, filtration, centrifugation and decantation, or by dissolution with water and phase separation, and, if desired, the filtrate can thereafter be distilled to improve the purity of the organo-methylene diphosphonate ester.

It may be necessary, however, when using organo halides containing substituent groups, such as, hydroxyl, carboxylic acid, and halides to protect these groups during the reaction. Usually the carboxylic acid groups can be protected by the well known method of esterification prior to the reaction and hydrolysis of the ester subsequent to the reaction. Also the hydroxyl group can usually be protected by the well known method of ether formation using such materials as dihydropyrane, benzyl chloride, tritychloride and the like to form the ethers followed by removal of the protective groups by such methods as hydroylsis with dilute mineral acids, catalytic hydrogenation, or chemical reduction. In addition, by using well known methods the halide group of polyhalide compounds can usually be protected by conversion into an ether group, a common reactant being sodium alkoxide, and the ether group subsequently cleaved with a hydrogen halide to remove the protective ether groups.

The organo-methylene diphosphonic acid can be prepared by the hydrolysis of the corresponding esters with a concentrated mineral acid. Generally, by refluxing the ester and a concentrated mineral acid, such as, HCl or HBr, at reflux temperatures for a period of usually about five hours is all that is necessary for the hydrolysis.

The salts of the organo-methylene diphosphonic acids can be prepared by neutralization of the acids with a stoichiometric amount of a base or a salt of a volatile acid that contains essentially the desired action. Bases or salts of volatile acids such as those containing an alkali metal, alkaline earth metal, aluminum, ammonia and amines are especially suited. For example, to make a sodium salt, one of organo-methylene diphosphonic acids can be neutralized with a stoichiometric amount of a base containing the sodium cation, such as NaOH, Na CO and the like. It should be noted that organo-methylene diphosphonic acid titrates using a pH meter as a tribasic acid, however, the tetra salts can be prepared by neutralization of the acids with a stoichiometric amount of a base and evaporating to dryness. In addition, it has been found if the acids are titrated using a pH meter in the presence of a 10% NaCl solution they will titrate as tetra-basic acids.

The following examples are presented to illustrate the invention, with parts by weight being used in the examples unless otherwise indicated.

EXAMPLE 1 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 288 grams tetraethyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about C. After all of the potassium is used up about 179 grams of n-heptyl bromide is added dropwise to the reaction mixture. To ensure a satisfactory degree of reaction the mixture is heated between about C. and 140 C. for about 10 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester as a colorless liquid. Analysis of the P n.m.r. spectra of the ester indicates tetraethyl octylidene diphosphonate, C H CH[PO(OC H with a small amount of impurity 5 of tetraethyl methylene diphosphonate. Elemental analysis yields the following results.

Calculated: C, 49.80%; H, 9.39%. Found: C, 46.82%; H, 9.51%.

EXAMPLE 2 The ester prepared according to Example 1 is hydrolyzed to the acid by refluxing about 386 grams with about 600 ml. concentrated HCl for about 5 hours. Evaporation to dryness yields the acid, octylidene diphosphonic acid, C H CH[PO(OH) The equivalent weight of this product, by titration, is found to be about 98.0 which compares favorably with the calculated value of about 91.3. Elemental analysis yields the following results.

Calculated: C, 35.00%; H, 7.29%. Found: C, 33.17%; H, 6.89%.

EXAMPLE 3 Trisodium octylidene diphosphonate C H CH [PO (ONa) [PO (ONa) (OH) is prepared by dissolving about 274 grams of free acid obtained as in Example 2 in about 1.2 liters of 10% NaOH solution and evaporating the aqueous solution to dryness at about 140 C. with the anhydrous form of the salt being formed.

EXAMPLE 4 Into a suitable reaction vessel about 39.1 grams potassium metal is added slowly to about 288 grams tetra-ethyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 65 C. After all of the potassium is used up about 247 grams of n-dodecylbromide is added dropwise to the reaction mixture. To ensure a satisfactory degree of reaction the mixture is heated at about C. for about 4 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester as a colorless liquid. Analysis of the P NMR spectra of the ester indicated tetraethyl tridecylidene diphosphonate,

Elemental analysis of this product yields the following results.

Calculated: C, 55.3%; H, 10.2%; P, 13.6%. Found: C, 54.28%; H, 10.58%; P, 12.97%.

EXAMPLE 5 Tetraethyl tridecylidene diphosphonate is hydrolyzed to the acid by refluxing about 454 grams with about 600 ml. of concentrated HCl for about 2 to 3 hours. Evaporation to dryness yields the acid, tridecylidene diphosphonic acid, C H CH[PO(OH) which is analyzed with the following results.

Calculated: C, 45.34%; H, 8.78%; P, 17.99%. Found: C, 44.86%; H, 8.71%; P, 17.90%.

5 EXAMPLE 6 Tri-ammonium tridecylidene diphosphonate,

C12H25CH[PO(ONH4)2] 4) 1' is prepared by dissolving about 334 grams of the free acid obtained as in Example in about 1 /2 liters of NH OH solution and evaporating the aqueous solution to dryness at about 120 C. with the anhydrous form of the salt being formed.

EXAMPLE 7 Into a suitable reaction vessel about 102 grams of 3- chloro-3-rnethyl pentane is added slowly to a potassiobutyl ester derivative reaction mixture prepared as in Example 1. To ensure a satisfactory degree reaction the mixture is heated at about 120 C. for about 6 hours. After filtering the potassium chloride, the reaction product is purified by distillation yielding tetrabutyl fl-diethylfl-methylethylidene diphosphonate,

EXAMPLE 8 Dicalcium cyclohexyl methylene diphosphonate,

C H CH[ PO(OCaO) 1 is prepared by dissolving about 322 grams of the free acid (cyclohexyl methylene diphosphonic acid), prepared generally by procedures used in Example 2, in about 1 liter of Ca(OH) solution and evaporating the aqueous solution to dryness at about 120 C. with the anhydrous form of the salt being formed.

EXAMPLE 9 Tetraethyl benzyl methylene diphosphonate CSH4CH[P(O) 2' 5)2]2 prepared generally by the procedures used in Example 1, is hydrolyzed to the acid by refluxing about 347 grams of the ester with about 80-0 ml. of concentrated HCl for about 4 hours. Evaporation to dryness yields the acid, benzyl methylene diphosphonic acid,

C5H4CH 2] 2 EXAMPLE l0 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 479 grams tetraphenyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 70 C. After all of the potassium is used up about 233 grams of 2-bromobiphenyl is added slowly to the reaction mixture. T 0 ensure a satisfactory degree of reaction the mixture is heat-ed at about 100 C. for about 8' hours. After filtering the potassium bromide, the reaction product is distilled yielding the ester, tetraphenyl biphenyl methylene diphosphonate,

s s s 4 lI s s) 2l2 EXAMPLE l1 Tetraethyl dodecylbenzyl methylene diphosphonate, (C H )C H CH[PO-(OC H prepared generally by procedure used in Example 1, is hydrolyzed to the acid by refluxing about 425 grams of the ester with about 800 m1. of concentrated HCl for about 4 hours. Evaporation to dryness yields the acid, dodecylbenzyl methylene diphosphonic acid,

EXAMPLE 12 Tetraethyl acetophenone methylene diphosphonate CH C( O)C H CH [PO( OC I-I prepared generally by procedures use-d in Example 1, is hydrolyzed to the acid by refluxing aout 405 grams of the ester with about 800 ml. of concentrated HCl for about 3 hours. Evaporation to dryness yields the acid, acetophenone methylene diphosphonic acid, CH C(O)C H -CH[PO(OH) l 6 EXAMPLE 13 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 288 grams of tetraethyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 70 C. After all of the potassium is used up about 333 grams of octadecylbromide is added slowly to the reaction mixture. To ensure a satisfactory degree reaction the mixture is heated at about 120 C. to 140 C. for about 10 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester, tetraethyl nonadecylidene diphosphonate, C H CH[PO(OC H Elemental analysis of the product gives the following result.

Calculated: C, 60.5%; H, 11.73%. Found: C, 63.07%; H, 11.49%.

Nuclear magnetic resonance analysis gives a P shift in p.p.m. of 23.9.

EXAMPLE 14 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 288 grams of tetraethyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 70 C. After all of the potassium is used up about grams of u-chloropyrrole is added slowly to the reaction mixture. To ensure a satisfactory degree reaction the mixture is heated at about C. to about C. for about 6 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester, tetraethyl pyrryl-1-methylene diphosphonate, C H N -CH [P(O)(OC H5)2].

Other methylene diphosphonate esters which can be reacted with metallic sources to form the metallo-cster derivatives, such as the potassio-ester derivatives, according to the procedures as illustrated by the foregoing examples include the following esters: tetramethyl methyl methylene diphosphonate, tetra-n-hexyl methylene diphosphonate, tetra-isopropyl methylene diphosphonate, tetra-dodeoyl methylene diphosphonate, tetrahexadecyl methylene diphosphonate, tetra-toluyl methylene diphosphonate, tetra-xylyl methylene diphosphonate, and the like, as well as mixed esters, such as, diethyldibutyl methylene diphosphonate, diethyl-di-n-hexyl methylene diphosphonate, dimethyl-diethyl methylene diphosphonate and the like.

Other halide compounds which can be reacted with the metallo-ester derivatives, such as the potassio-ester derivatives, according to procedures as illustrated by the foregoing example to form compounds of the instant invention include aliphatic hydrocarbyl halide compounds, such as, 3-chloro-2-rnethyl butene-l; 3-chloro-2-methyl butene-2; 2-chloro-2-methyl pentane; 3-chloro-2,2-dimethyl butane; 4-chloro-2,2-dimethyl butane; 3-chloro- 2,2,3-trimethyl butane; 3-chlorohexane; n-hexyl chloride; n-undecyl chloride; n-hexadecyl chloride; n-hexyl bromide; n-octy1 bromide; n-dodecyl bromide; n-tetradecyl bromide; l-bromo-n-caproic acid; 2-bromo hexanoic acid and the like.

Alicyclic halide oompounds include cyclopentyl bromide, cyclohexyl chloride, cycloheptanyl chloride, cycloheptanyl bromide, cyclopentadiene dibromide, cyclohexane carboxylic acid chloride, l-chloro-l-methyl cyclohexane, 3-bromo-cyclohexene, 3-chloro-cyclohexene, 2- chloro-cyclopentadiene, 2-bromo-cycloheptanone, 1,2-dibromo cycloheptane, 1-b-romo-4-tertbutyl-cyclohexane, l-chloro-l-methyl cyclohexane, 1,2-dibromo cycloheptane, 1-chloro-3-methyl cyclohexane, and the like.

Aryl halide compounds include the mono-cyclic arylhalide compounds, such as, chlorobenzene, 2-chloroaniline, 2-amino-4, 6-dichloro phenol bromobenzene, 4-bromo aniline and the like, as well as the polycyclic aryl halide compounds, such as, 3-chloro bip-henyl, 4- amino-4-chloro biphenyl, 2-chloro-1-napthal, 2-ch1oroanthraquinone, l-chloro-napthalene, l-bromo-napthalene, 2-bromo biphenol, and the like.

Alkaryl halide compounds include benzyl chloride, fl-phenyl ethyl chloride, 4-methyl benzyl chloride, 3- methyl benzyl chloride, 2-methyl benzyl chloride, 2-chlorobenzyl chloride, 4-chlorobenzyl chloride, 3-chlorobenzyl chloride, 4-isopropyl 'benzyl chloride, m-xylene dichloride, a-chloro acetophenone, benzyl chloroformate, benzyl bromide, ,B-phenyl ethyl bromide, 2-bromo 'benzyl 2-bromo biphenyl, and the like.

Aralkyl halide compounds include 2-chlorotoluene, 3- chlorotoluene, 4-chlorotoluene, 1-chloro-2-ethyl benzene, 2-chloro-2-vinyl benzene, l-chloro-Z-isopropyl benzene, 2-chloro-4-isopropyl-l-methyl benzene, p-chloro benzoic acid, 2-chloro-4-octyl phenol, 2-chloro-4-nonyl phenol, 2-chloro-4-dodecyl phenol, 2-benzyl-4-chlorophenol, 2- bromotoluene, 1-bron1o-4-ethyl benzene, 4-bromoacetanilide, 4-bromoacetophenone, phenaryl bromide, 4-bromobenzoic acid and the like.

Heterocyclic halide compounds include N-chlorosuccinimide, N-bromo succinimide, 2-chloropyridine, 2-chloroquinaline, 2-bromo-5-nitro furan, 2-bromo-5- methyl furan, S-bromo indole, S-bromo-Z-methyl indole, 4-bromo-2-picoline, 3-chloropyridine, 4-chloropyridine, 3-bromothiophene, 2-bromo-3, 4-dinitro thiophene, 2- chloro thiophene, 2-bromofuran, 3,4dichloro-tetrahydrofuran, 3,4-dichloro-2, S-diphenyl furan, S-bromo-indole, 4-chloro indole, 7-chloro-2, 3-dimethyl indole, 2-chloro-l, 4,6-trimethyl indole and the like.

Other bases or salts of volatile acids which can be reacted with the free acids to produce salt compounds of the instant invention according to the procedures as illustrated by the foregoing examples include the inorganic alkali metal, alkaline earth metal and aluminum salts, oxides and hydroxides, such as, NaCl, NaNO Na O, Na C KOH, K 0, KC], K CO KNO LiOH, LiCl, LiNO Li CO CsOH, CsCl, CsNO CsCO CaCl CaO, CaCO Mgcl MgO, MgCO BaCO BaCl Ba(OH) Ba(NO CrCo SrCl Sr(OH) A1(0H A1 0 Al(NO and amines, such as, ethyl amine, diethylamine, propyl amine, propylene diamine, diethylene triamine, hexyl amine, Z-ethylhexyl amine and the like.

Quite unexpectedly organo-methylene diphosphonic acids or the salts thereof were found to exhibit not only good deflocculating or dispersing properties and sequestration properties but also good surfactancy properties. It is highly unusual for all of these properties to be effectively exhibited by the same compound. As can be appreciated, such compounds can advantageously be utilized in applications which can use the foregoing properties, a

such as, detergent compositions. In many detergent applications such as textile cleaning including synthetic textiles and hard surface cleaning, the ability of the detergent composition to remove the soil, keep the soil suspended in the washing medium, as well as, exerting a water softening effect in the washing medium by sequestration of calcium and magnesium ions, is of paramount importance.

The higher alkalidene diphosphonic acids or the salts thereof are preferred in applications which use the combined surfactancy, sequestration and defiocculating properties. These compounds are of the following formula:

ROOZ

Z 0 o 2 wherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl radicals containing from to 20 carbon atoms and Z is a cation selected from the group consisting of hydrogen ion, alkali metal cation, alkaline earth metal cation, aluminum cation, ammonium ion, and amine ion.

As used in detergent compositions, the compounds of the instant invention are preferably formulated with other components which may include other surface active compounds (actives) as Well as builders such as sodium tripolyphosphate and tetrapotassium pyrophosphate, antiredeposition agents such as carboxymethyl cellulose and the like, brightening agents, perfumes and the like, in amounts between about 5% to 50% by weight of the detergent composition. The resulting detergent composi tion is generally effective when used in aqueous systems in conventional amounts such as is normally used with detergent compositions and which is generally about 5% concentration or below.

Compounds illustrative of the invention were tested for surfactancy properties by determining surface tension measurements with a du Nuoy Tensiometer in dis tilled water at room temperature. The compounds tested were at concentrations believed representative of detergent concentrations used in actual applications. The results of the test are tabulated below.

TAB LE I Surface Tension (dyne/cn.) at

As can be observed from the above table, compounds illustrative of the invention, i.e., (2) and (3), exhibit the ability to lower the surface tension of water (4). Compounds (2) and (3) compared very favorably with sodium dodecylbenzene sulfonate (5), a widely used surfactant, when used in molar concentrations of 5X10- and 10- It should be noted that compound (1) exhibited no appreciable surfactancy ability since a compound exhibiting a surface tension above about at molar concentrations of 5 10- and 10- is not usually, regarded as a surfactant. As can be appreciated, therefore, by reason of their surfactancy, compounds of this invention are particularly well suited for use in detergent compositions.

Compounds illustrative of the invention were tested for deflocculating properties in a carefully controlled kaolin slurry. The kaolin used in the evaluation was essentially free of impurities and was placed in an aqueous slurry with a solids contents about 68%. The slurry throughout the evaluation was maintained at a pH of about 7 with NaOH or HCl. The apparent viscosity was determined with a Stormer Viscometer at 300 rpm. The results of the tests are tabulated below.

TABLE 2 Apparent viscosity in centipoises at 300 r.p.m. Stonner at indicated As can be observed from the above table, minor amounts of the compounds illustrative of the invention, i.e., (2) and (3) deflocculated a plastic slurry into a flowable slurry. In addition, compounds (2) and (3) compared very favorably with sodium tripolyphosphate (4), a widely used deflocculant, and compound (1) when 9 used in amounts of about .1 and .15 weight based on a dry clay basis.

Compounds illustrative of the invention were tested for sequestration properties. The conditions of the test were to dissolve .25 gms., of the tetrasodium salt of the compound of the instant invention and .25 gms. of

in 250 ml. of Water and adjust the pH to 12 with NaOH. To the solution is added 0.1 M Ca(NO until a cloudy endpoint, i.e., the precipitation of CaC O is achieved. In order to calculate the pounds of calcium sequestered by 100 pounds of material tested, the volume of 0.1M Ca(NO used, in cc. units, is multiplied by 1.6. The results of the test are tabulated below.

TABLE 3 Lbs. calcium/100 lbs. of compound (1) Tetrasodium octylidene diphosphonate Compound:

C H CH[PO(ONa) (2) Tetrasodium tridecylidene diphosphonate C12H25CH[PO(ON3.)2]2

As can be observed from the above table, compounds illustrative of the instant invention, i.e., (1) and (2) exhibited the ability to sequester calcium, thus indicating their beneficial use in aqueous systems containing such IOIIS.

The esters of organo-methylene diphosphonic acids were found not only to be substantially miscible with water but also highly soluble in organic solvents, such as hydrocarbon solvent, i.e. hexane and pentane, carbon tetra chloride, haloethylene solvents (perchloroethylene), ethers, alcohols, and the like. Also, the esters were found to impart a solubilizing action to water in water-immiscible solvents, such as many of the previously mentioned solvents. This totally unexpected property renders them highly useful as gasoline de-icer additives and along with their surfactancy properties renders them useful as dry cleaning detergents. As can be appreciated, however, the unique ability to impart a solubilizing action to water in water-immiscible solvents can be utilized in many and varied applications and, therefore, the foregoing mentioned applications are merely indicative of their use.

The esters of higher alkylidene diphosphonic acids are preferred in applications which use the combined surfactany and/or water solubilizing properties. These compounds are of the following formula:

wherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl radicals containing from to 20 carbon atoms and R R R and R are selected from the class consisting of alkyl groups of from 1 to 20 carbon atoms, aryl hydrocarbyl groups and alkaryl groups with the lower alkyl groups being especially preferred.

Because of the complexity of the ternary solubility diagram of the esters of the instant inventionwaterwaterimmiscible solvents the following is set-forth for example purposes only.

A solution of cc. of hexane and 5 cc. of the following esters of the higher alkylidene diphosphonic acids dissolves the amounts of water at room temperature indicated in Table 4. The water was added dropwise until permanent cloudiness or phase separation was observed. The tabulated results are presented in the following table.

Table 4 Compound: H O added (cc.)

(1) Tetra ethyl octylidene diphosphonate C H CH [PO(OC H .5 (2) Tetra ethyl tridecylidene diphosphonate C H CH [PO(OC H 2.5

It should be noted that the foregoing example solutions exhibited no phase separation at the end of a one week period of standing nor was there a phase separation after the solutions had been centrifuged at 5,000 r.p.m. for one hour indicating that the water Was completely dissolved in the water-immiscible solvent. It should further be noted that tetraethyl methylene diphosphonate, CH [PO(OC H did not impart a solubilizing action to water in a water-immiscible solvent.

As previously mentioned the ester compounds of the instant invention are useful in gasoline as de-icer additives and are preferably used in amounts of from .005 to 5% by weight. An advantageous feature of these de-icer additives, by reason of their phosphorus content, is their ability to function either wholly as the primary additive for surface ignition control or in conjunction with other known phosphorus additives for surface ignition control.

As dry cleaning additives the ester compounds of the instant invention can be used as either the primary surfactant or in conjunction with other surfactants. When used as substantially the primary surfactant with many of the common organic solvents, such as, Stoddards solvent and perchloroethylene, amounts within the range of .05% to 10% by weight are usually sutficient with amounts about 2% by weight being preferred.

In addition, the ester compounds of the instant invention may also be as extractants for metals in an aqueousorganic solvent system.

Although the compounds of the instant invention as well as their uses have been described with a degree of particularity, the invention herein is intended to be limited only by the claims set forth hereinafter.

What is claimed is:

1. A gasoline composition consisting essentially of (a) gasoline and (b) from about 0.005% to about 5.0% by weight, based on the total weight of said composition of an ester of an organo-methylene diphosphonic acid, said ester having the formula wherein R is selected from the class consisting of aliphatic hydrocarbyl groups of from 7 to 30 carbon atoms, and alicyclic, aryl, alkaryl, aralkyl groups of from 5 to 30 carbon atoms, and X is selected from the class consisting of aliphatic hydrocarbyl, aryl, alkaryl, and aralkyl groups having up to 30 carbon atoms.

2. A gasoline composition consisting essentially of (a) gasoline and (b) from about 0.005% to about 5.0% by weight, based on the total weight of said composition of an ester of a higher alkylidene diphosphonic acid, said ester having the formula wherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl groups containing from 5 to 20 carbon atoms and R R R and R are selected from the class consisting of alkyl groupsof from 1 to 20 carbon atoms, and aryl hydrocarbyl groups and alkaryl groups having up to 30 carbon atoms.

References Cited UNITED STATES PATENTS 2,897,071 7/1959 Gilbert 4469 2,999,739 9/1961 Heron 4469 3,093,672 6/1963 Miller 4469 DANIEL E. WYMAN, Primary Examiner.

W. I. SHINE, Assistant Examiner. 

